Sains Malaysiana 43(1)(2014): 103–109

 

Combustion Characteristics of Refuse Derived Fuel (RDF) in a Fluidized Bed Combustor

(Ciri Pembakaran Bahan Api Janaan Sampah (RDF) di dalam Pembakar Lapisan Terbendalir)

 

 

A. JOHARI*, R. MAT, H. ALIAS, H. HASHIM, M.H. HASSIM, Z.Y. ZAKARIA & M. ROZAINEE

Institute of Hydrogen Economy, Faculty of Chemical Engineering, Universiti Teknologi Malaysia

81310 Johor Bahru, Johor, Malaysia

 

Received: 28 September 2012/Accepted: 9 April 2013

 

ABSTRACT

The combustion characteristics of refuse derived fuel (RDF) in a fluidized bed have been studied. The gross heating value (GHV) of the RDF was 14.43 MJ/kg with moisture content of 25% by weight. Parameters of interest for sustainable bed combustion were the fluidization number and primary air factor. The study was performed in a rectangular fluidized bed combustor with dimensions of 0.3 m in width, 0.7 m in length and 2 m in height. Sand with mean particle size of 0.34 mm was used as a fluidization medium. The sand bed height was at 0.3 m above the standpipes air distributor. The range of fluidization number under investigation was 5–7 Umf in which 5 Umf was found to be the optimum. The study was continued for the determination of the optimum primary air factor with the selected range of primary air factors being 0.6, 0.8, 1.0 and 1.2 in experiments conducted at 5 Umf. The final results showed that the optimum primary air factor was at 0.8. An energy balance was also performed to determine the thermal efficiency of the combustion. It was concluded that the thermal efficiency depended on the bed temperature and the primary air factor being used.

 

Keywords: Air factor; fluidized bed combustor; fluidization number; operating parameter; refuse derived fuel (RDF); thermal efficiency

 

ABSTRAK

Ciri pembakaran bahan api janaan sampah (RDF) di dalam pembakar lapisan terbendalir telah dikaji. Nilai pemanasan kasar (GHV) bahan api tersebut adalah 14.43 MJ/kg dan mempunyai 25% berat kandungan air. Parameter yang dikaji untuk pembakaran lestari di dalam pembakar lapisan terbendalir adalah nombor pembendaliran dan faktor pengudaraan utama. Kajian dilakukan di dalam pembakar lapisan terbendalir bersegi empat bersaiz 0.3 m lebar, 0.7 m panjang dan 2 m tinggi. Pasir dengan saiz purata 0.34 mm telah digunakan sebagai medium perbendaliran. Ketinggian lapisan pasir adalah 0.3 m dari pengagih udara. Julat nombor pembendaliran yang dikaji adalah dari 5 – 7 Umf dan keputusan menunjukkan 5 Umf adalah nilai optimum. Kajian diteruskan bagi mendapatkan faktor pengudaraan utama optimum dengan nilai 0.6, 0.8, 1.0 dan 1.2 dan uji kaji dilakukan pada 5 Umf. Keputusan menunjukkan faktor pengudaraan utama yang optimum adalah 0.8. Kecekapan terma pembakaran tersebut diperoleh dengan pengiraan imbangan tenaga dan didapati bahawa kecekapan terma adalah bergantung kepada suhu lapisan pembakaran dan faktor pengudaraan utama yang digunakan.

 

Kata kunci: Bahan api janaan sampah (RDF); faktor udara; kecekapan terma; nombor pembendaliran; parameter operasi; pembakar lapisan terbendalir

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*Corresponding author; email: anwar@cheme.utm.my